It’s a fairly odd situation. Sean Kelly is supposedly here to promote his new stand-up show. However, the wags at the Guide have decided that we should instead recreate his role in the phenomenally popular TV show Storage Hunters. So now we’re staring at the front of a cupboard.

Storage Hunters, the blind-auction show in which competitors bid on abandoned lock-ups in nondescript parts of the USA in the hope of finding forgotten treasure, has become a TV sensation. Dave screens both the original and its recent-ish UK remake seemingly non-stop to meet public demand for its vicarious thrills.

“This $80 chest is stuffed with Ming vases!” “This $600 shed is full of pissy futons!” On Storage Hunters there are no guarantees, besides Kelly’s funny noises, and rival bidders threatening to punch each other in the neck.

Here, at the Guide locker, I’m eyeing up something that looks valuable: a Professor Green gold disc. “It’s not actually a gold disc. It’s just celebrating his gold disc sales. This is basically just a picture frame,” says Kelly, knocking the glass, which wobbles because it’s Perspex. He revises his opinion. “It’s worth less than a picture frame.” It’s a bum start, but things are looking up. I pull out some pieces of history: a copy of the New York Times dated 4 Nov 2008, the day Barack Obama became President. Underneath it are bundles of Guides (dating back to 2003, when the Coral were still a thing). I could probably sell these on at a hefty profit, right? “Oh yeah. Let’s see: original price a buck fifty? Now you could probably get one POUND fifty.” He’s being sarcastic, which is fine. What about the Guides? “Yeah. So if you wanted to start a fire in your flat, these can help with that.”

I don’t know where he picked up this attitude, possibly his unlikely sounding early adulthood working in military intelligence in Germany, “debriefing” members of the former East German Stasi. Either way, Kelly is cutting a sarcastic swath through the contents of my locker. A box of Rizzle Kicks teabags (“Oh wow… that is genuine crap”), a plastic, secondhand record player (“Do you have between a two- and a five-year-old at home?”), and a toy Citroën, still in box (“Anything made in China is good”). I honestly don’t know why the Guide has all this stuff. It’s a locker full of rubbish, lacking logic or value. I pull out a T-shirt covered in foreign phrases. “Dónde está…” reads Kelly. “That’s good, you can learn to say, ‘Dónde está my money? Where has my money gone?’”

After Berlin, Kelly shipped out to Iraq, to serve in Desert Storm (“I had top security clearance, but I’m the last person you wanna trust with a secret”). He eventually returned to the USA, hustling at car boot sales. The day he walked into a storage auction, he knew he wanted to make a TV programme out of it, though he had to put himself through auction school first. That must have been noisy.

Kelly attributes the show’s success to one thing: characters more irritating than a dose of thrush. “The buyers can’t hold down regular jobs because their personalities are too abrasive. This is how they’ve learned to make a living, shouting at each other. For me it’s like watching a carnival, except they have no social skills at all.”

This sounds a bit rich from the man now openly laughing at my dud haul. A Pantone colour chart and a mannequin’s leg – seriously, who are the psychopaths who work here? – are worth nothing.

“If you were lucky you could make £17 total. You’re £303 upside down, man. Ha ha!” He finds a roll of crime-scene tape in the locker, and covers my entire lot with it. “This is a crime scene. Literally, what you just bought is a crime scene. It’s a crime because of how much money you’re losing.”

“YES, I GET IT,” I say.

I ask Kelly about his stand-up act, as I was meant to half an hour ago – “I make fun of the Germans a lot. And my wife, who’s a germaphobe” – but feel depressed, having thrown all my money into a cupboard full of crap. Or have I? There’s one item left. Reaching far back into the space, I pull out… a clay pigeon. Made of plastic. It’s a plastic pigeon.

“Look there’s a hole in the bottom,” Kelly laughs. “You can pretty much smell your investment right there.” Thanks, Sean. He tots up my losses. “Any guy who spends £300 on a locker like this is welcome at my auctions, because I make 30%. I’m the only one who’s made any money today. I’ve made £90.”